Method of heating and apparatus therefor



July 30, 1940- w. E. LOBO v METHOD 0F HEATING AND APPARATUS THEREFOR Filed May 2o, 1957 2 Sheets-Sheel l INVENTOR WALTER E. Loo

(gjm, [1X-MM ATTORNEY July 30 1940- w. E. LOBO 2,209,341

METHOD 0F HEATING AND APPARATUS THEREFOR Filed May 20, 1937 Sheets-Sheet 2 mm-mcmmmm INVENTOR vrroRNEY Patented July 30, 1940 PATENT OFFICE METHOD F HEATING AND APPARATUS THEREFOR Walter E. Lobo, Westfield, N. J., assignor to `Gasoline, Products Company, Inc., Newark,

N. J., a corporation of Delaware Application May 20, 1937, Serial No. 143,744

"#1 v i 7 Claims.

This invention refers to a method and apparatus for heating fluids and relates in particular to such method and apparatus wherein a plu- W. rality of separate continuous streams of hydro- J* carbon fluids are heated to a conversion temperature within a single furnace setting.

It' is an object of the invention to provide a new and improved method and apparatus for n" heating a plurality of separate streams of hydrocarbon fluids' under entirely different temperature conditions Within a single furnace structure and for controlling such heating by regulating the quantityof hot products of combus- 0 tion introduced into the various parts of the furnace and the distribution of such products within the furnace. f Other objects and advantages reside in the method, structure, arrangement and combination of parts hereinafter described and illustrated in Q0 the accompanying drawings in which like reference characters are used to designate like parts in the several views and in which:

Fig. 1 is a sectional eleva-tion of a furnace constructed in accordance with the invention,

and

Fig. 2 is a similar view vof a modified furnace structure.

Referring to the drawings and Fig. 1 in particular, reference character I refers in general to a unitary furnace structure comprising an elongated box-like chamber. A plurality of bridge walls 2, 3 and 4 extend between opposite lateral boundaries of the chamber and serve to divide the same into a pair of combustion sections 5 and G and a pair of convection sections 1 and 8. The convection sections 1 and 8 are arranged between the combustion sections 5 and 6 and separate the combustion sections from each other.

Suitable means, such as burners 9 extending through ports ID, are provided on both the front and back walls of the furnace for introducing fuel to be burned or already formed hot products of combustion into each of the combustion chambers 5 and 6. The number and arrangement of the burners or the like may be varied to suit the requirements of a particular installation. Each of the burners or other means for introducing the fuel or hot products of Y combustion is independently adjustable to regulate the quantity of such products introduced thereby.

Each of the convection sections 1 and 8 is in open communication with both of lthe combustion sections 5 and 6 across the bridge walls 2,

` 3, :and 4 and is thus adapted to receive hot lprod--A ucts of combustion from either o-r both of the combustion sections. The bridge walls are spacedy from the roof to form a substantially horizontal passageway through which combustion products pass after leaving the combustion sections; The 5i hot products of combustionthus withdrawn from the combustion sections and received by the con-` vection sections are passed downwardly through the convection sections and withdrawn from the furnace by means `of separate ducts or the like 10:

communicating with the bottom of each convection chamber. As'illustrated in the drawings, a duct I I communicates withth'e convection sec-` tion 1, a duct I2 communicates with the convection section 8, and a duct I3 communicates I5:

with both of the said vducts jIl and I2 and serves to convey the hot products'of combustion Withdrawn from the furnace to a stack or other apparatus.I A `damper I 4 is arranged in the ductr II leading from the convection section 1, and* a 20 damper .I5 is positioned in thevseparate duct I2" leading from' the "convection section 8. The dampers I4 and I5 may be manually or automatically cc` ntrolledl by any'suitable or desired means and `may be operated independently of 25 eachother orasl a unit. By setting the dampers in predetermined' positions the quantity of ue gases passing through each of the convection sections may be accurately regulated.

A plurality Vof tubesis arranged adjacentone 30' or more boundary surfacesxof each of the combustion sections 5 and '6,' and aplurality of tubes is disposed in each of the convection-sections '1 and 8. 'I'he tubes withinv the combustion sections 5 and 6 are'positioned substantially out of the 35 path of hot products of combustion iiowing there` through and are adapted to be heated predomie' nantly by radiant heat. The tubes disposed within the convection sections 1 and 8 are arranged in the direct path of the hot products of com- 40 bustion passing through the convection sections and are heated predominantly by convection heat. The tubes in the combustion and convection sections may be interconnected in any desired' sequence for the passage of one or more 45 fluids therethrough in single or plural streams, and tubes in one or both combustion sections may be connected to tubes in the convection sections for the passage of .uids through such sections in any desired sequence. 50

There Ais illustrated in the drawings an arrangement' of the tubes which may be advantageously employed with the method and apparatus of the invention. Asshown, tubes I6 may be placed adjacent the bridge wall 2v and-tubes. 55

I1 may be placed adjacent the roof in the right half of the combustion section 5, as viewed in the drawings. These tubes are preferably connected to form a continuous coil. Tubes I8 may be placed adjacent the end wall and tubes I9 may be placed adjacent the roof in the left half of the combustion section 5. These tubes are likewise preferably interconnected to form a second continuous coil. The tubes in the upper portion of the convection section I are interconnected to form two separate coils 20 and 2| positioned in the respective right and left halves of the convection section, and the tubes in the lower portion of this convection section are interconnected to form two other separate coils 22 and 23 likewise positioned in the respective right and left halves of the convection section. Tubes 24 may be placed adjacent the other end wall and tubes 25 may be placed adjacent the roof within the combustion section E. These tubes are also preferably interconnected to form a single coil. The tubes arranged within the convection section 8 are likewise interconnected to form a single coil 26 within said section. The coils 20 and 2| in the upper portion of theconvection section 'I are connected respectively with the coils formed by tubes I8, I9, and tubes IB, I'I, in the respective left and right halves of the combustion section yby tubes 21 and 28, diagrammatically shown. The opposite ends of the coils positioned within the combustion section 5 are interconnected respectively with the coils 23 and 22 positioned within the lower portion of the convection section 1 by lines 29 and 3i), diagrammatically shown. A line 35 connects the upper portion of the coil 26 positioned withinthe convection section 8 with the lower portion of the coil positioned in the combustion section t formed by tubes 24 and 25. f

With such arrangement a separate stream of hydrocarbon uids may be introduced Vinto the upper portions of each of the coils 2!) and 2| by means of the lines 3| and 32, respectively, passed downwardlyl through said coils, thence through the coils connected thereto in the combustion section 5, and thence downwardly through the coils 22 and 23 connected to the separate coils in the combustion section 5. The separate streams are withdrawn from the lower portions of the coils 22 and 23 by means of the lines 33 and 34. A third stream of hydrocarbon fluid may be introduced by means of line 36 into the lower portion of the coil 26 positioned in the convection section 8 and passed upwardly through said coil in a direction countercurrent to the flow of hot products of combustion through the section. This stream is then introduced into the lower portion of the coil positioned within the combustion section 6 by means of the line 35 and is withdrawn from the furnace by means of line 37 after passage through the tubes 24 and 25.

The two streams which are introduced into the lines 3| and 32 may, for example, comprise normally gaseous hydrocarbons which are heated, with or without the addition of higher-boiling constituents, to a conversion temperature in the convection section 'I and combustion section 5 for the purpose of cracking and /or polymerizing the same to form constituents boiling in the range of gasoline. Such temperature may be, for example,

750 to 1200 F. while under a pressure of 500- 3000 pounds. The coil positioned within the convection section 8 and combustion section 6 may be used as a reboiler coil in connection with such polymerization process. In such application of the apparatus and method of the invention the dampers lli and I5 are so adjusted that a portion of the hot products of combustion from the combustion section 6 and all of such products from the combustion section 5 are introduced into the convection section I to maintain a higher temperature in such section than in the convection section 8.

It is to be understood, however, that the invention contemplates the passage of any desired hydrocarbon uids, either liquid or gaseous, through any one or more of the various sections of the apparatus to be heated therein to a cracking or polymerising temperature. It is also to be understood that the invention is not limited to the particular arrangement of tubes and the ow of iiuids therethrough thus illustrated and described, but contemplates any desired arrangement of tubes in the various sections of the furnace and any desired interconnections between such tubes. While I have only shown and described wall and roof tubes in each combustion section, it is to be clearly understood ythat suitable oor tubes, positioned below the burners and heated predominantly by radiant heat, may also be used in either or both of the combustion sections.

Any desired temperature may be maintained in each of the combustion sections 5 and 6 by regulating ythe quantity of fuel to be burned or already iormed hot products of combustion introduced into each section by means of burners or the like 9. The convection sections separate the combustion sections and permit an entirely different temperature to be maintained in each of the combustion sections as well as in each of the convection sections. The bridge walls defining the convection sections not only shield the tubes within the convection sections from direct radiant heat in the combustion sections but also shield the tubes in each combustion section from the radiant heat in the other combustion section. The temperature within the diierent convection sections is controlled by adjusting the dampers I4 and I5 positioned within the ducts and I2 and thereby regulating the portion of hot products of combustion from the combustion sections which is distributed to and passed through each convection section. Since each of the convection sections 'I and is in open communication with both combustion sections 5 and 6 a portion'or all of the hot products of combustion withdrawn from the two combustion sections may be passed through either of the convection sections to increase the heat therein. In this manner the temperature of the convection sections and the amount of heat imparted to the respective streams of fluids therein may be Varied as desired.

Fig. 2 of the drawings illustrates a modification of the invention in which a bridge wall 4' is positioned adjacent an end wall of the elongated chamber to provide a convection section 8 adjacent such end of the furnace. The convection section 8 is in direct communication with the combustion section 6 across the bridge wall 4 and communicates with the combustion section 5 across the bridge walls 2 and 3'. The convection section I communicates directly with the combustion sections 5' and 6 across the bridge walls 2' and 3', respectively. In this arrangement the tubes 24 in the combustion section 6 are positioned adjacent the bridge wall 4. A separate duct I2 having a damper I5 therein communicates with the convection section 8', as in the arrangement of Fig. 1. The temperature and distribution of the hot products of combustion within the various sections ofthe furnace are controlled and varied as in the furnace illustrated in Fig. 1 of the drawings. The arrangement of Fig. 2

may be found desirable where only a portion of the hot products of combustion from the combustion section 6' is required in the convection section 8', and also where it is desired to pass, for example, a portion of the hot products of combustion from combus-tion section 5 through the upper portion of section 6' to the convection section 8.

The furnace may be divided into any desired number of separate combustion sections by arranging one or more convection sections between the adjacent combustion sections, and one or more separate convection sections similar to 8 of Fig. 2 may be associated with the combustion sections 5 and 6 of Fig. 1. Instead of separating the radiant sections with one or more convection sections, as illustrated in the drawings, the radiant sections may be separated by a suitable bridge wall with a convection section at the end of each radiant section for receiving hot products of combustion from its adjacent or both radiant sections. Thus each radiant section may be separated from its adjacent convection section by a suitable bridge wall, and suitable dampers, as illustrated, may be provided, for the purposes described, below each convection section.

The various interconnected tubes illustrated in Fig. 1 have been shown as being connected for dual ow, that is, a single stream of hydrocarbon fiuid divided into two substantially equal parts for passage therethrough. It is to be clearly understood that the tubes of a furnace constructed in accordance with my invention may be connected in any desired manner to effect the desired ow therethrough.

Many other modications and variations may be made without departing from the spirit and scope of the invention and only such limitations should be imposed as are included in the appended claims.

I claim:

1. The method of heating separate continuous streams of hydrocarbon fluids in a heating apparatus comprising a chamber provided with a plurality of bridge walls disposed to separate the chamber into a pair of combustion sections and a pair of convection sections with at least one of said convection sections being positioned between the combustion sections and with each of said convection sections being adapted to receive hot products of combustion from both of said combustion sections, which comprises directly introducing hot products of combustion into each of said pair of combustion sections, distributing substantially al1 of said products of combustion from one of said combustion sections and a part thereof from the other combustion section to one of the convection sections and the other part of said products of combustion from the last mentioned combustion section to the other of said convection sections, passing a separate stream 'of hydrocarbon fluid through each combustion section and a different one of said convection sections, and heating said streams predominantly by radiant heat from said hot products of combustion in the combustion sections and predominantly by convection heat from such products in the convection sections.

2. The method of heating separate continuous streams of hydrocarbon fluids in a heating apparatus comprising a chamber provided with a pair of combustion sections separated by two sepdrocarbon fluid through each combustion section and a different one of said convection sections, and heating said streams predominantly by radiant heat from said hot products of combustion in the combustion sections and predominantly by convection heat from such products in the convection sections.

3. The method of heating separa-te continuous streams of hydrocarbon fluids in a heating apparatus comprising a chamber provided with a pair of combustion sections separated by a pair of convection sections each adapted to receive hot products of combustion from both of said combustion sections, which comprises directly introducing hot products of combustion into each of said pair of combustion sections, distributing substantially all of said products of combustion from onel of said combustion sections and a part of the products of combustion from the other combustion section to one of the convection sections and the other part of said products of combustion from the last mentioned combustion section to the other of said convection sections, passing one stream of hydrocarbon fluid through a conduit extending through the upper portion of said convection section receiving hot products of combustion from both of said combustion sections and then through one of said combustion sections and then through said last mentioned convection section below said conduit, passing another stream of hydrocarbon fluid through said other convection section and then through .l said other combustion section, and heating the streams predominantly by radiant heat from said hot products of combustion in the combustion sections and predominantly byk convection heat from such products in the convection sections.

4. The method of heating separate continuous streams of hydrocarbon fluids in a heating apparatus comprising a chamber provided with a pair of combustion sections and a pair of convection sections, each convection section being adapted to receive hot products of combustion from both of said combustion sections, one of said convection sections being arranged between two combustion sections and the other convecn tion section being arranged between one of said combustion sections and the end of said chamber, which comprises directly introducing hot products of combustion into each of said combustion sections, distributing substantially all of the products of combustion from one of said combustion -sections and a part of the combustion products from said other combustion section to said convection section between said combustion sections and' distributing the other part of the combustion products from the last mentioned `combustion section to said other convection section arranged adjacent an end of said chamber, passing a separate stream of hydrocarbon iiuid through each combustion section and a different one of said convection sections', and heating said streams predominantly by radiant heat from said hot products of combustion in the combustion sections and predominantly by convection heat from such products in the convection sections.

5. A heating apparatus for heating separate streams of hydrocarbon uids including a housing having a roof, a plurality of vertically arranged bridge walls of substantially the same height and spaced from said roof and dividing said housing into a pair of combustion sections separated by a pair of convection sections, each of said convection sections communicating with both of said combustion sections over said :bridge walls so that combustion gases leaving said combustion sections pass in substantially horizontal and unobstructed flow before being passed through certain of said convection sections, means for withdrawing hot products of combustion from said convection sections, means including a bank of tubes positioned adjacent a boundary surface .of each of said combustion sections for passing a separate stream of hydrocarbon iiuid through each of the combustion sections to be heated therein predominantly by radiant heat from said hot products of combustion, means including a bank of tubes arranged in the path of hot com-bustion products passing through said convection sections for heating a separate stream of hydrocarbon fluid in each of said convection sections, and means associated with each convection section adapted to cause substantially all of the combustion products leaving one of said combustion sections and passing in substantially horizontal unobstructed flow and a part of the combustion products leaving the other combustion section and passing in a substantially horizontal unobstructed flow to pass through one of said convection sections and the other part of the combustion products leaving said last mentioned combustion section and passing in a substantially horizontal unobstructed flow to pass through the other convection section.

6. A heating apparatus for heating separate streams of hydrocarbon uids including a housing having a roof and providing an elongated chamber, a plurality of spaced vertically arranged bridge walls of substantially the same height extending between opposite lateral boundaries of said cham-ber and dividing said chamber into at least two combustion sections and two convection sections, said bridge walls being spaced from said roof to provide an unobstructed, substantially horizontal passageway connecting combustion sections and said convection sections, said bridge walls being so arranged that two combustion sections are separated by. and communicate with at least one of said convection sections and that a second of said convection sections communicates directly with at least one of said combustion sec-tions, separa-tely adjustable means for introducing hot products of combustion into each of said combustion sections, means for withdrawing hot products of combustion from said convection sectionsy means including a bank of tubes positioned adjacent a boundary surface of each of said combustion sections for passing a separate stream of hydrocarbon fluid through cach of the combustion sections to be heated therein predominantly by radiant heat from said hot products of combustion, means including a bank of tubes arranged in the path of hot combustion products passing through said convection sections for heating a separate stream of hydrocarbon fluid in each of the convection secQ1 tions, and means associated with each convection section adapted to cause substantially all of the combustion products leaving one of said combustion sections and passing in horizontal, unobstructed flow through a-t least a portion of said passageway a'nd a part of the combustion products leaving another of said combustion sections and passing in horizontal unobstructed flow through at least a portion of sa-id passageway to pass through one of said convection sections and the other part of the combustion products leaving said last mentioned combustion section and passing in horizontal unobstructed flow through at least a portion of said passageway to pass through another of said convection sections.

7. A heating apparatus for heating separate streamsof hydrocarbon fluids including a housing having a roof, a plurality of spaced vertically arranged bridge walls of substantially the same height and spaced from said roof and dividing said housing into a pair of combustion sections separated vby a convection section communicating with both of said combustion sections across said bridge walls so that combustion gases leaving said combustion sections pass in a substantially horizontal and unobstructed flow before being passed through said convection section, another vertically arranged bridge wall adjacent an end of said housing and providing another convection section adjacent an end of said housing and communicating with said combustion sections across said bridge walls, said last mentioned bridge wall being of substantially the lsame height as said first mentioned bridge walls and being spaced from said roof so that combustion products leaving said combustion sections pass in a substantially horizontal and unobstructed flow before being passed through said last mentioned convection section, separately adjustable means for introducing hot products of combustion into each of said combustion sections, means for withdrawing hot products of combustion from said convection sections, means including a bank of tubes positioned adjacent a boundary surface of each of said combustion sections for passing a separate stream of hydrocarbon fluid through each of the combustion sections to be heated therein predominantly by radiant heat from said hot products of combustion, means including a bank of tubes arranged in the path of hot combustion products passing through said convection sections for heating a separate stream of hydrocarbon fluid in each of the convection sections, and means associated with each convection section adapted to cause substantially all of the combustion products leaving one of said com'bustion sections and passing in a substantially horizontal unobstructed ow and a part of the combustion products leaving the other combustion section and passing in a substantially horizontal unobstructed flow to pass through said convection section between said combustion sections and the other part of the combustion products leaving said last mentioned combustionsection and passing in a substantially horizontal unobstructed iiow to pass through said convection section adjacent one end of said housing.

WALTER E. LOBO. 

